Automatic feed pump especially for locomotive boilers



June 19, 1928.

5. SZABO AUTOMATIC FEED PUMP ESPECIALLY FOR LOCOMOTIVE BOILERS Filed Au 2 Sheets-Sheet l l v u MN m i Q l June 19, 1928.

' s. szAB AUTOMATIC FEED PUMP ESPECIALLY FOR LOCOMOTIVE BOILERS Filed Au 51. 1925 2 Sheets-Sheet Patented June 19, 1928.

UNITED stares ear" sAnnon SZABO, or BUDAPEST, HUN-GARY.

AUTOMATIC FEED PUMP ESPECIALLY LQCOM 'OTIVE BOILERS.

Application filed August 31, 1925, Serial No. 53,759, and. inHungary August 16, 1 924.

This invention relates to apparatus for the automatic regulation oi the working of the feed pumps of steam engines and especially locomotives.

It has hitherto been found necessary with feed-pumps for boilers to put as much Water in the boilers, particularly locomotive boilers, as is used by the power cylinders.

In known feed-regulating apparatus, the Variation in the number of revolutions and the admission or feed of the steam engines have only been taken into consideration although, in a great proportion of travelling steam'engines, particularly locomotives, the consumption of the steam has been influenced by the inflowing steam pressure, as well as by the number of revolutions and the admission of steam to the engine. 7

The object of the present invention is the production of apparatus which positivelyoperates the feed-pumps of the boilers of steam engines, particularly locomotives, in such amanner, that, the said pumps dependent uponthe number of revolutions, the in-v coming steam pressure, and the admission or feed of "steam, automatically feed to the boiler as much water as corresponds to the steamvused by the'power cylinders.

According to the invention, the piston of the fced pump is driven by a rod, the strokes ofwhieh are equalin number to those of the power cylinder piston. and the length of stroke of which isdetermined by lever mechanism," regulated by a servo-motor, operated by a liquid, this operation being conjointly dependent upon'the amount or degree of pressure and of the admission of the steam entering the cylinder or cylinders of steam engine. l

In, the accompanying drawing- Figure 1 is a diagramof the general arrangement of the apparatus in accordance withthe invention." a

Figure 2 is a diagram of the parts actuate ing the servo-motor but drawn to a larger scale.-

Figure? is a diagram of a practical form;

of the servo-motor actuating mechanism.

Figure 4 is a plan view and a diagrammatic side view of a second practical form of the servo-motor mechanism.

One end of a driving-rod 7), Figure 1, is

the

serving as a driving member, which is os cillated by means of the intermediate 'rod' To the driving-rod p is also connected the actuated piston-rod s oi the servo-motor by means of the slidinglink 3. The position in;

height of the servo piston-rod is regulated by the inflowing steam 'pressureand the a dmission of steam to. the engines in a manner heremaiterdescribed and causes the link 3 correspondingly to vary its point of conneclength of movement ofth-e driving rod 32 so.

that the length of. stroke offlthe plungerP of the feed-pump 1S dependent upon the pressure of the inflowing steam and the fadmission ot the steam to the engine cylinders The lever mechanismin the present case 7,

70, tion with .the rod Z3 and consequently the comprises the servopiston-rod 8 and the sliding link 3 which latter is moved up and down on the rod 7e by the said rod 8 and which is attached the drivingrod p, and this lever mechanism only isret 'erred to in the specification; i I 7 As the number of the strokes of the feedpump is dependent on the number ofrevolutions of the steam engine, and the-length of stroke on the pressure and admission oi'the inflowing steam, the output of the feedpump isproportional to the number of revo:

lutions of the steam engine 'to, the pressure, and the admission of the inflowing steam, that is. to say, the teed-pump will simulta--. neously,with the strokes ot'thesteam engine, pump as much water into the boiler as; is necessary for replacing the" steam used in. the power cylinder, whereby the water level. in the boiler will be keptconstant.

The conjoint controlling of the servo-mm tor S with respect to the movements of the servo piston-rod s bythe infiowing steam; pressure and thesteam admission is effected in the, following manner v One end of-alevor 1 Figures 1 and. 2, which 1 term a return lever is linked to the upper end of the servo-rod a, whilstithe other and bifurcated end of this lever is con nected. bymeanso't the pivot IILgwhichQis guided parallel with the rod of the pres-f sure transmitter N, to the bifurcated end ot another return lever 60,, the otherend of which is pivoted to the end I of the relayrod 7" by means of. which the known double piston-valve T of the relay R is operated.

In the slot- II of the return lever 40 is pivotally fixed the pressure transmissionrod n which, by means of the pressure transmitter N, Figure 1, presses the-said lever upwards in accordance with the pressure of the infiowing steam.

If the inflowing steam pressure falls off,

' for example, from 12'atm. to 6 atm. see Figrest, if the double piston T is put in the poure 2, the return lever x will be pulled down the whole length by the pressure transmission rod n into the position corresponding to 6 atm., whereby the relay rod 1' will be also moved down and also the double piston T of the relay B, so that water pressure will be exerted under the piston of the servomotor S by way of'the tubes al 6, b Figure '1, the superfluous water above the said piston flowing through the tubes 0 0, 6 into the suction pipe of the said pump, so that the servo-rod s is raised, whereby the sliding link 3 on the arm 75 reaches a higher position and, as a result, the stroke of the plunger P is reduced. A smaller stroke of the plunger of the feed pump therefore corresponds to a smaller pressure in the steam engine. The piston of the servo-motor S comes t sition shown in Figure 2, which then results in the case of 6 atm., when the end V of the return lever y reaches the position V and" the link III the position HP.

The feed-pump can be put out of operation by closing the tube 9 of the pressure transmitter N, Figure 1, and by releasing the steam or water present in' the saidpressure transmitter. The fitting D, Figure 2, serves to limit the movement of the return lever in and to relieve the relay rod '1".

The return lever 3 is pivoted or fulcrumed by a slide pivot IV, to a sliding bearing which isadjusted for example, by the valve gear ofthe steam engine, the movements of I which areproportional to the admission of steom to the steam engine. The path of this bearing is so measured that the piston of the servo-motor S,.Figure 1, takes, with the largest admission, the lowest, and with the smallest admission (0) the highest position, whereby the sliding link 3, on the arm 70, also moves from the lowest to the highest positionso that the effective stroke of the plunger P is changed from, its greatest to its smallest value. To the greater and smaller admission of the steam engine there fore correspond a greater and smaller stroke of the feed-pump.

As in the position corresponding to the (O) admission Figure 2, the joints IV and V of the servo piston-rod s coincide in'the position'V that is to say, the return stops, the oint IV is not allowed to go below the ing pivot on the return lever 3/ attached to the piston rod of the servo-motor as in Figure 2, but to a sliding pivot on the return lever w.

The operation of this form will be obvious in view of that illustrated in Figures 1 and 2.

Figure 4 illustrates the second practical form of thefinvention and'its operation will also be obvious in view of the prior de scription.

In this form, the return lever y is formed I as a single-armed lever, to a pin A' on'which, the forked end of the transmitting lever 2 is secured.

Within the limits of its construction and action, the characteristics of the present invention may be modified freely without the invention itself sufiering any alteration. thereby.

Thus, an increase of theoutput of the feed-pump may be obtained by arranging that the relay be moved independently of the return levers in any position of the same.

This may be done, for example, by dividing the relay rod in two parts by means of Ia double-armed lever, the pivot of which is diagonally movable.- i 1 The relay and the servo-motor'need'not be connected to the pressure and suction spaces of the feed-pump, but it is sufficient if the flow of liquid filling thetwo spaces of the servo motor, from one of the said liquidspaces to the other is controlled'and that only in the required direction'by means of the above described operation'of the'rela'y. The piston of the servo-motor is, through the medium ofth servo-rod during each stroke of the feed-pump, under, theinfluence of a force acting ina changing direction and the said piston can consequently move in the corresponding direction when'the re: lay allows the flow of the liquid on that'side.

Having now'particularly described and ascertained the nature of my said invention and in what manner the same is to be performed I declare that what I claim is:

1. Apparatus for automatically regulating the out-put of the feed pump of a steam en'- gine, including a fiuidoperated servo-motor, means dependent on the pressure and the feed of the steam flowing to a power cylinder of'the engine for controlling the' op-' eration of the servo-motor, a driving rod for the feed pump, mechanism for actuating said rod, and means interposed between the actuating mechanism and the driving rod for varying the stroke of said rod, said means beingoperatively connected with and actuated by said servo-motor.

2. An apparatus as claimed in claim 1, in which the means dependent on the pressure and the feed of the steam flowing into a power cylinder of the engine for controlling the movement of the servo-motor, includes a relay, the movement of the latter being dependent on the pressure of the inflowing steam to a power cylinder of the engine and on the admission.

3. An apparatus for the automatic regulation of the out-put of the feed pump of a steam engine having a power cylinder, including a driving rod for the feed pump, mechanism for actuating said driving rod and adapted tobe driven by the steam engine, a device interposed between the driving rod and said actuating mechanismrfor varying the stroke of said driving rod, a piston operatively connected to said device, a cylinder in which the piston operates, said piston and cylinder forming a servo-motor, a valve mechanism, for controlling th flow of fluid to and from the servo-motor, a link mechanism connecting said piston to the valve mechanism, and a transmitting'device actuated by the steam flowing to the power cylinder of the engine, said transmitting device being operatively connected to the link mechanism and being adapted to cause the latter to shift the valve mechanism for controlling the movements of said piston.

4:. An apparatus as claimed in claim 3, in which the link mechanism includes a slidable element slidable on one of the links of the link mechanism for varying themovement of the link mechanism.

In testimony whereof I aifix my signature Budapest, 14th August. 1925.

sANnoR szABo. 

